jRuby Experimenting with Clojure’s PersistentHashMap in JRuby I benchmarked some tests run in JRuby that compare the Hamsterdam library using Hamster's immutable Hashes vs Clojure's PeristentHashMap, plus some gotchas.
Ruby Defining Immutable Record Types in Ruby with Hamsterdam Hamsterdam is a Ruby gem that makes it fun and easy to define and use efficient immutable record types in Ruby, backed by Hamster's Hash class.
jRuby Preventing JRuby Concurrency Errors with Hamster How using Hamster's efficient, immutable, thread-safe collections can prevent ConcurrencyError exceptions in JRuby.
